Merge pull request #123 from reaper7/master

new input device PCF8574KeyIn.h

Author: neu-rah

src/menuIO/PCF8574KeyIn.h

@@ -0,0 +1,89 @@
+/* -*- C++ -*- */
+
+/**************
+todo: write description
+***/
+
+#ifndef __PCF8574KeyIn_h__
+  #define __PCF8574KeyIn_h__
+
+  #include "../menu.h"
+  #include <Wire.h>
+
+  namespace Menu {
+
+    #include "keyMapDef.h"
+
+    #ifndef BOUNCE_TICK
+    #define BOUNCE_TICK 30
+    #endif
+
+    //if you hold/repeat a key for this ammount of time we will consider it an escape
+    #ifndef ESCAPE_TIME
+    #define ESCAPE_TIME 1500
+    #endif
+    //emulate a stream keyboard, this is not using interrupts as a good driver should do
+    // AND is not using a buffer either!
+    template <int N, int _dev=0x20, int _sda=SDA, int _scl=SCL>                 //default pcf8574 address=0x20
+    class PCF8574KeyIn:public menuIn {
+    public:
+      keyMap* keys;
+      int lastkey;
+      TwoWire iicWire;
+      unsigned long pressMills=0;
+      PCF8574KeyIn<N, _dev, _sda, _scl>(keyMap k[]):keys(k),lastkey(-1) {}
+      void begin() {
+        iicWire.begin(_sda, _scl);
+      }
+      int available(void) {
+        int ch=peek();
+        if (lastkey==-1) {
+          lastkey=ch;
+          pressMills=millis();
+        }
+        else if (ch == -1 && millis()-pressMills < BOUNCE_TICK)
+        {
+          lastkey = -1;  //released = it's bounce. reset lastkey
+          return 0;
+        }
+        else if (ch != -1 && millis()-pressMills > BOUNCE_TICK) return 1;
+        else if (ESCAPE_TIME&&millis()-pressMills>ESCAPE_TIME) return 1;
+
+        if (ch==lastkey) return 0;
+
+        return 1;
+      }
+      int peek(void) {
+        //Serial<<"peek"<<endl;
+
+        iicWire.requestFrom(_dev, 1);
+        uint8_t val = iicWire.read();
+
+        for(int n=0;n<N;n++) {
+          int8_t pin=keys[n].pin;
+          if (((val)&1<<pin)==0) {
+            //Serial<<"key "<<pin<<" pressed"<<endl;
+            return keys[n].code;
+          }
+        }
+        return -1;
+      }
+      int read() {
+        //Serial<<"read"<<endl;
+        int ch=peek();
+        if (ch==lastkey) return -1;
+        int tmp=lastkey;
+        bool longPress=ESCAPE_TIME&&millis()-pressMills>ESCAPE_TIME;
+        //Serial<<"read lastkey="<<lastkey<<" ch="<<ch<<endl;
+        //Serial<<"down time:"<<millis()-pressMills<<endl;
+        pressMills=millis();
+        lastkey=ch;
+        return longPress?options->getCmdChar(escCmd):tmp;//long press will result in escape
+      }
+      void flush() {}
+      size_t write(uint8_t v) {return 0;}
+    };
+
+  }//namespace Menu
+
+#endif